In U.S. patent application Ser. No. 07/406,933 filed Sept. 13, 1989 by A. Ballato and J. A. Kosinski for "Method of Making a Resonator From A Boule of Lithium Tetraborate and Resonator So Made" and assigned to a common assignee and with which this application is copending, there is disclosed and claimed a method of making a resonator from a boule of lithium tetraborate. The method includes the steps of:
(A) orienting the boule with respect to its crystallographic axis and cutting the boule into parallel plates having a doubly rotated orientation of .phi..congruent.38.degree. to 42.degree. and .theta..congruent.30.degree. to 36.degree. where doubly rotated orientations are described by the IEEE notation widely known in the art as (Yxwl).phi./.theta.,
(B) lapping and polishing a plate from step (A) and depositing metallic electrodes onto the major surfaces of that plate; and
(C) mounting the plate in an evacuated sealed enclosure to form a resonator and subjecting the resonator to an alternating voltage across the electrodes at a frequency that piezoelectrically excites the fundamental harmonic of the thickness extensional mode.
Though highly desireable in its attributes for the thickness extensional mode, the method of Ser. No. 07/406,933 does not work for shear mode applications. In this connection, there are many instances where it is desireable to use the shear mode, as for example, in measuring the shear elastic constants of composite materials and superlattices.